History of Computers - P2P Networks
Page created by Brett Gutstein, 22 August 2011
Peer to Peer (P2P) Networks
Peer to peer (P2P) networking is a distributed application architecture that lacks a central server. In peer to peer networks, members make a portion of their resources available to other members of the network, so peers are both suppliers and consumers of resources. Computers in P2P networks run the same networking protocols and software and share equal responsibility for processing data.
<- Server Based Network <- Peer to Peer Network
Peer to peer networks can be configured over LAN or the Internet. Local area P2P networks can be configured to be either wired or wireless and allow the sharing of files, printers, and other resources between involved computers. Over the Internet, P2P networks can handle an extremely high volume of file sharing because the workload is distributed across many computers worldwide. Internet based P2P networks are less likely to fail or experience a traffic bottleneck than client-server networks for the same reason.
The basic idea of P2P networking has been around since 1969, when the Internet Engineering Task Force pusblished its first Request for Comments. However, the first dial-up P2P network was created in 1980 in the form of Usenet, which was a worldwide Internet discussion system. The difference between other web forums and Usenet was that Usenet did not depend on a central server or administrator-- it was distributed among a constantly changing group of servers that stored and forwarded messages to one another in bursts called news feeds. Individual users could read messages from and post messages to a local server, which would then send posted messages around the world.
The next advancement in P2P networking came in 1990 with the release of Napster. In addition to being a P2P network, its network consisted of a single server that was solely used to bootstrap the system and serve indexing functions. Napster allowed users to easily share files, primarily mp3s, worldwide. Users with the Napster software and a shared partition on their computer could query the internal server for the song they were looking for. The internal server would find a different user that had the song in his or her shared partition, and a connection would be established between the two machines. The person searching for the song would then download the song from the person who owned it, and the connection would be terminated when the download was complete.
The problem with Napster was that it gave users access to music for free, violating record labels' copyrights. Napster faced a number of lawsuits, and courts ordered Napster to monitor its network and prevent the sharing of copyrighted material. Due to the nature of P2P networks, however, Napster was unable to do so and shut down in July 2001. Since then, many other P2P programs that serve the same function as Napster have been created, and although some have been shut down, there have always been functional ones to take their places.
P2P networking was extremely significant in the history of computers because it allowed the sharing of files and information worldwide. It also allowed for the creation of extremely large networks because of the shared workload among machines in the network. Some such networks include Spotify, Skype, cloud computing networks, and government networks. BitCoin is a P2P based internet currency. Another popular use of P2P networks is BitTorrent, a method of rapidly downloading large files from multiple people at once. 
P2P networking has had a profound effect on the music and film industries. Though the economic effect of P2P networks is controversial and somewhat hard to determine, the music industry reported a 6 billion dollar drop in annual sales from 1999 to 2003. Likewise, the MPAA reported that they lost 2.3 billion dollars to internet piracy in 2005 alone.
Also, P2P networks are now commonplace in the computing world. In 2004, 70 million people engaged in file sharing.  A CBS poll in 2009 reported that 70 percent of Americans under 30 thought that file sharing was acceptable. Today, P2P networks give computer users access to any files or programs imaginable, free of charge. However, with this availability comes a decision: is it ethical to obtain paid and copyrighted programs for free over P2P networks?